Tuesday, December 13, 2016

BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA

DAILY DISCUSSION AND CLIMATE SUMMARY
TUESDAY, DECEMBER 13, 2016

DRY CONDITIONS RETURN UNDER PARTLY SUNNY SKIES

Increasing pressure gave us lower dew points and visibility
reaching 70 miles today.  Temperatures started slightly cooler
than yesterday morning but were still able to rise to a max. of
40F by 1:00PM. Westerly winds became light by early afternoon.
Although skies turned broken by early afternoon, they were mostly
cloudy with cirrus and allowed abundant sunshine.

7 A.M.
Weather: Few cumulus NNW-S, scattered cirrus
Temperature: 31F; Dew Point: 21F; Wind: W at 12 kts
Sea-level pressure: 30.06 ins. Hg, rising, then more quickly
Visibility: 70 miles
6-hr Max temp: 32F
6-hr Min temp: 30F
24-hr precip: 0.15 in.
BHO SA 1155 250 SCT 70 181/31/21/2812/006/ FEW CU NNW-S/
8/101 53025 MANUAL 70015 ASOS 70019 10032 20030

10 A.M.
Weather: Few cumulus NNE-E, scattered cirrus
Temperature: 35F; Dew Point: 22F; Wind: W at 8 kts
Sea-level pressure: 30.13 ins. Hg, rising, then more slowly
Visibility: 70 miles
BHO SA 1455 250 SCT 70 204/35/22/2708/013/ FEW CU NNE-E/
8/101 51023

1 P.M.
Weather: Broken cirrus
Temperature: 40F; Dew Point: 19F; Wind: W at 4 kts,
Wind Speed: Light
Sea-level pressure: 30.11 ins. Hg, falling, then more slowly
Visibility: 70 miles
6-hr Max temp: 40F
6-hr Min temp: 30F
BHO SA 1755 E250 BKN 70 197/39/19/2804/011/ WND LGT/
8/001 56007 10040 20030

SUMMARY FOR MONDAY, DECEMBER 12, 2016

TEMPERATURE (DEGREES F)
MAX…..41   NORMAL…..40
MIN…..27   NORMAL…..25
MEAN….34   NORMAL…..33

DEPARTURE FROM 30-YEAR NORMAL……………………+1
TOTAL DEPARTURE FOR THE MONTH……………………-7 [-0.8 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..31   DEPARTURE……….-2
TOTAL HEATING UNITS FOR THE MONTH………….372   DEPARTURE……….+6
TOTAL HEATING UNITS FOR THE SEASON………..1402   DEPARTURE……..-225
TOTAL HEATING UNITS LAST SEASON TO DATE……1252   DIFFERENCE…….+150

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….29 ESE AT  5:32 A.M.
ASOS……………………29 SE  AT  5:58 A.M.
DAVIS…………………..28 ESE AT  5:57 A.M. RMY N/A
FASTEST MILE FOR YESTERDAY…………………23 ESE AT  7:17 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………21 SW  AT 11:15 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..21 ESE AT  7:19 A.M.
AVERAGE WIND SPEED AND DIRECTION………….13.1 SW
ASOS………………….13.2
DAVIS…………………11.8 S [190 Deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.15  DEPARTURE……-0.02
ASOS…………..0.19
TOTAL PRECIPITATION FOR THE MONTH……….0.84  DEPARTURE……-1.14
ASOS…………..0.93
TOTAL PRECIPITATION FOR THE YEAR……….37.81  DEPARTURE…..-12.70
ASOS………….38.36

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……….0.0  DEPARTURE…….-0.4
TOTAL SNOWFALL FOR THE MONTH…………….1.7  DEPARTURE…….-2.3
TOTAL SNOWFALL FOR THE SEASON……………1.7  DEPARTURE…….-4.9

PRELIMINARY CLIMATE SUMMARY FOR DECEMBER CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/PEAK GUST/AERO/RMY GUST
AERO: Aerovane wind recording system gust
RMY:  R.M. Young wind gust recording system
TSTM: Thunderstorm day (thunder heard some time during day)
….: Data not yet available, records not finalized
M:    Missing data

12/1  55/39/47/+10/0.20/0.0/385/69          36 W   AERO 37 W   RMY 36
12/2  48/34/41/+5/0.00/0.0/535/96           32 W   AERO 32 W   RMY N/A
13/3  44/31/38/+2/0.00/0.0/…/..           37 WNW AERO 39 WNW RMY 40
12/4  39/27/33/-2/0.00/0.0/…/..           25 NW  AERO 25 NW  RMY N/A
12/5  36/27/32/-3/0.13/0.4/…/..           26 W   AERO 25 W   RMY 29
12/6  42/30/36/+1/0.00/0.0/…/..           22 W   AERO 21 W   RMY N/A
12/7  39/34/37/+3/0.10/0.0/…/..           21 E   AERO 21 E   RMY N/A
12/8  40/29/35/+1/0.00/0.0/…/..           30 W   AERO 31 W   RMY 33
12/9  35/21/28/-6/0.00/0.0/…/..           35 W   AERO 36 WNW RMY 34
12/10 27/17/22/-11/0.00/0.0/…/..          26 WNW AERO 27 WNW RMY 29
12/11 33/16/25/-8/…./…/…/..           17 SSW AERO 15 SW  RMY N/A
12/12 41/27/34/+1/…./…/…/..           29 ESE AERO 29 SE  RMY N/A

12/13 Low temp since midnight is 30F; normal low is now 25F

DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):

RECORDS FOR DECEMBER 13
HIGH 60 IN 1984
LOW 0 IN 1893
PRECIP 1.45 INS. IN 1983
SNOWFALL 9.2 INS. IN 2007
PEAK GUST 81e WNW IN 1976

RECORDS FOR DECEMBER 14
HIGH 62 IN 1901
LOW -6 IN 1893
PRECIP 1.94 INS. IN 2002
SNOWFALL 8.0 INS. IN 1907
PEAK GUST 78e ENE IN 1941

TODAY’S REPORT PREPARED BY: Cecilia Borries-Strigle